Rectal administration of low-dose diclofenac does not reduce post-endoscopic retrograde cholangiopancreatography pancreatitis: a propensity score matching analysis

Background Endoscopic retrograde cholangiopancreatography (ERCP) is a popular technique; however, post-ERCP pancreatitis (PEP) remains a major adverse event. The administration of rectal nonsteroidal anti-inflammatory drugs (NSAIDs) is reportedly effective in preventing PEP. However, the recommended dose varies and the efficacy of low-dose rectal NSAIDs remains unclear. Therefore, we decided to investigate the effectiveness of low-dose rectal diclofenac on PEP prevention, using propensity score matching. Methods This single-center retrospective study included 401 patients who underwent ERCP between July 2015 and March 2020. After December 2016, we administered rectal diclofenac within 30 min before the ERCP procedure as widely as possible. Patients were divided into those who did (diclofenac group) and did not (control group) receive rectal diclofenac. Patients weighing ≥ 50 kg were administered a 50 mg dose, while those weighing